It's interesting that Catholics are slightly overrepresented on this forum (in comparison to the US in general), while Protestants are very, very underrepresented. (Clearly non-Christians are overrepresented as well, but that's not at all suprising). Do Protestants not use the internet? (I mean this in a sort of toung-in-cheek way, obviously Protestants use the internet)
Protestants identify less with "Protestant" (and more with a particular denomination or just "Christian") than Catholics do with "Catholic", so probably less likely to vote in this sort of poll.